title: Clinical significance of translocation t(1;19) in childhood acute lymphoblastic leukemia in the context of contemporary therapies: a report from the Children's Cancer Group.
abstract: OBJECTIVE
  The nonrandom translocation t(1;19) has been associated with poor outcome in pediatric B-lineage acute lymphoblastic leukemia (ALL). Because most patients treated by contemporary therapies now achieve improved outcomes, we have reassessed the prognostic significance of t(1;19).
  
  
  METHODS
  Cytogenetic data were accepted for 1,322 children (<21 years old) with newly diagnosed ALL enrolled between 1988 and 1994 on risk-adjusted studies of the Children's Cancer Group (CCG). Forty-seven patients (3.6%) were t(1;19) positive (+); 1,275 (96.4%) were t(1;19) negative (-). Clinical characteristics and treatment outcome were compared using standard methods.
  
  
  RESULTS
  Translocation (1;19)+ patients were more likely than t(1;19)- patients to be 10 years of age or greater (P < .001) or CD10+ CD19+ CD34- (P < .0001), or nonwhite (P = .02). Patients with a balanced t(1;19) were less likely to be hyperdiploid than patients with an unbalanced der(19)t(1;19). Event-free survival (EFS) was similar for the overall group of t(1;19)+ and t(1;19)- patients, with 4-year estimates of 69.5% (SD, 6.8%) and 74.8% (SD, 1.3%; P = .48), respectively. However, patients with unbalanced der(19)t(1;19) had significantly better outcomes than patients with balanced t(1;19): 4-year EFS were 80.6% (SD, 7.1%) and 41.7% (SD, 13.5%), respectively (P = .003). These differences were maintained within the individual studies analyses and after exclusion of t(1;19)+ patients whose cells were hyperdiploid with more than 50 chromosomes.
  
  
  CONCLUSIONS
  The overall group of t(1;19)+ patients, as well as the subgroup with an unbalanced der(19)+ (1;19) had outcomes similar to that of t(1;19)- patients, whereas patients with balanced t(1;19) had poorer outcomes. Thus, although the overall prognostic significance of t(1;19) has been obviated by contemporary risk-adjusted protocols, the balanced t(1;19) translocation remains an adverse prognostic factor.
authors.affiliation: Children's Cancer Group ALL Biology Reference Laboratory and Wayne Hughes Institute, St. Paul, MN 55113, USA. faitih-uckun@mercury.lh.org
authors.forename: F M
authors.initials: FM
authors.lastname: Uckun
authors.forename: M G
authors.initials: MG
authors.lastname: Sensel
authors.forename: H N
authors.initials: HN
authors.lastname: Sather
authors.forename: P S
authors.initials: PS
authors.lastname: Gaynon
authors.forename: D C
authors.initials: DC
authors.lastname: Arthur
authors.forename: B J
authors.initials: BJ
authors.lastname: Lange
authors.forename: P G
authors.initials: PG
authors.lastname: Steinherz
authors.forename: P
authors.initials: P
authors.lastname: Kraft
authors.forename: R
authors.initials: R
authors.lastname: Hutchinson
authors.forename: J B
authors.initials: JB
authors.lastname: Nachman
authors.forename: G H
authors.initials: GH
authors.lastname: Reaman
authors.forename: N A
authors.initials: NA
authors.lastname: Heerema
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D007621:Karyotyping; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000276:immunology / Q000628:therapy; D011379:Prognosis; D014178:Translocation, Genetic